SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec7fd442f9adfde15fad1a9c5d639d63e4c31cc59ec919539a53ff65c9d69543' 
  AND token = 'ptjGRJ/Sur9qubZPkcbwfv1yYF3aBb8upap13l/tR74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}