SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0413b20011d9d465af8db62bdbc264f9ff415242785bbbdee3644af1b3a1372' 
  AND token = 'wxTM1i/8UTOjAnH8lYxQ/uiSclgsoNB9iCl1Uc2ybtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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