SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '801ecd913b66c05d82b7b23cb64515823ce53414a413084fa96e6fb7f0be2114' 
  AND token = 'rWdeGId07xrQaKqmbbiAj5rqLpsjKL4YOns0JQvWvM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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