SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1cabb33228cda78995006118414face6bcb0d096fc3841df9fdf5efac50031e' 
  AND token = 'uixiXA0SGvyvDc0Xd9nlDisSppT/F/zqKqvDGzW+c8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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