SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad44a9bde79f80c37a3bbf98b14efad60bf47dfd0b55f4839220018f13191680' 
  AND token = 'VQOFYlDnGreG5g06BOD6Q1UkZNuNddIAkL57JvKL3xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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