SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec89a7e8d683fa41148c7f7977086a24c3abbf10cce9f6455d83e90a416b5968' 
  AND token = 'VpGjGUomGjaPjfSMeqpMyYxZ8LWkB+rBD04Wt9NIOXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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