SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3f424601be1a395dae0c435a7ef9cbac02a83c03f314cf8a11e1588443c46be' 
  AND token = 'tvE2kBnUuNK0kEUMp0FsTRHZpbs2EKjnS4CZMrygoOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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