SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e713317f9548c175937e81d57f5c80fd0279f2e3b4f8dad686b2a36d69dd4ea3' 
  AND token = 'hcAkVDr4LvbCr5YgryhZjkQvDAnGwlKCPnvTHQ5Us0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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