SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '666b17416b4c5a5b460f55429e07ceccb2851196719562b076d5ef8e949b89eb' 
  AND token = 'vwbfbL7/FFvEenGCW7vfFEm28YTsvQCgLShD+SzmZJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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