SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba4bcbba360924edad749052af4abd131d26aa02834afbd15d43c0918176a0d6' 
  AND token = 'WZdN47dJZ+/355xKfX47jlpKlqwIA8I0QEvqJrLcPQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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