SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f93b622dbe9dce0e1325270629007ff6ebce21670d3a6877f3575dfa26adcc' 
  AND token = 'rJWY5us3mu6KnVZUDi39gKk9B11bTLSCjZVQiHGbLh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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