SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2159f2bdd3c8da1186754ca4b8797736987d293f14adb4e00b6695882d51f62f' 
  AND token = 'p1tNtFnyXZVIfwVHLawXnVWbQywHbSj77P5Zrq0AHRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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