SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f33ef107f81fc5c01b7b4aa304898ddcdbbf000c5c172b696993b83c6ea7f1b8' 
  AND token = 'h4UfhpN+FKxWHtWLPSudnEMrPKchcQJMtze50f1feII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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