SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99fa9d27740e50482ed1d48bad67ac71934af9d88458f795b5bbbfd06ded6c14' 
  AND token = 'WRh/BN41WfaOy5esIEuiCfJQYhRqfhP+fAjDyMdUu6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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