SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6dec8318d990bc37c34d31d0957c4e27e2b0c8a1ddeeb5718764eb27abc8ba81' 
  AND token = 'JtjiNHo+C4VsCcswCvMFgXLqLn+MaJOP+OwPYpGZ2ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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