SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b2932f54ea3fec226855b6424edfa83de6c1a37d5fa792baaa09b903a6223f9' 
  AND token = 'Kbv5RsaqQMtg57dgVfKHoIidmaFjNt2Vabkf0fTOEaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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