SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f391128369ca5d3b1fc532e207f978255f0605123611a4a05d957d14293865c0' 
  AND token = 'zq1CYOihpUEdjYZIpHDbN2EwvDAGJTCmyu9ol1kuCKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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