SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49a08a71f26ee88777184209d4645d196194cda90b3f9584b6ace04f3b0bd55c' 
  AND token = 'U+mSxNuoq/7R91QQWwyet4Vlhv24Lq0bQu/lpTZ2/9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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