SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4313ba680a3dd56edf395214aa8d61dfc2a17812be5135afbc20c45d10619b17' 
  AND token = 'PcFEKxv7VoEZuipqlHiGYqkwyfJVSbGeREeLgIojMRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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