SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd470a20ea35f9d015e51321d59100363fcf9e0faee0a0fe2888c0b6b12bda4b1' 
  AND token = 'fYUl5fPWeczA+26WrZH8JTpkz1KIR2MIiauAr4hLHPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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