SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c01ae9f4d1544db2369b739a6931b7a1e9fe9280b0d9be035f319f10094c8624' 
  AND token = 'W1uVbVZuM/5hyYSnxB5F78IUJvbIvIzqrscIaASn0eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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