SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '241ff12e64e38bc3263719006f0d7a991d0f1846c25e82e7630da54899c65900' 
  AND token = 'HxVEbrVJAmcSLKst81vwCN6DMXXW21TrLPzxkEuIK5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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