SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '291f21b19064867e57fe00d1b420e2333b5bfbcbb808346ea975b375742248b7' 
  AND token = 'D/FQIRgKbuMV04fWuYTxIOMLx/eFmchwXoHH+WaK2pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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