SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e98b92c048361a0127741d5415df5aee6ac123dae6ff82b8c68fc4aa0f961042' 
  AND token = 'PrYvom08Ftpl+z/4GnacZGhxXEMWMq7fO3LdR1jooJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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