SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c399868064bc3c2a3051fd0ec2fcc99382a608469ce0553370ddf1f53c35628' 
  AND token = 'Dkz8I98hqK2hHR5LKYj8Vy/QF+0VcsORyC7nEmjpQBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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