SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be46b5341fb43bea91599bcb389f8f1148f03c25fe7e94658bce41e056af4d72' 
  AND token = 'BZyktvNJUJmYHwUk++RgtL9GqNzYmry9Ev9UywVxnvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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