SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e6cb72885dce7c00b94734f6cd28afd14258f8f4a05ecdec40504e8c20a425f' 
  AND token = 'yJoeKirUKfPYyrwmGzNMDIy4+dc88EI+Hzz/pjegnTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}