SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6f7cfc1bb4a3873dde41d01e74618161e0c197bdca6736fead84b97248ca7c6' 
  AND token = 'VRTgqynw8jyrfQQ6jNOEWF2y5u7MXK58QUvAGliVn3c=' 
  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"
    }
  }
}