SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '850ad95a470b429040f2af76dce901d1701a1d70138315db582e5586d59886b7' 
  AND token = 'FfzHP2eVBmVnEEHg1gzc1fGiGZ5TXwh4cYySDLESTic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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