SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e76ea2d2565a792345c99b84222e0d9fd434d5acd55b29516f49a3c68be44cf' 
  AND token = 'IZ+wi7vwZ/9Y7wNB5zgVEetr1oB/5G1jFmIa1jeEYBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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