SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6601af5500f94a99e7ee84e74f56c2a99276c2be86508961a3a6bf9870e930ee' 
  AND token = '4xARJI6Z3wssvi4x9tC8tUsPIDz2UsFKtxfZoXaghhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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