SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ca69bd802307ea7bd402af09bc8bab54d43feba549bec6baef6d77707c1f1ba' 
  AND token = 'wts8H3vI7FaxlklwXGaazRJGOZzdWo6Ki9HOD+r+A4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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