SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75f63253d6540972e9b133a040115a8121d55d19a2d418daa64a4016b359f672' 
  AND token = 'Tw+l7TcYSeFV1ZPKVGMyEouVWjrt7ExUZRYgJAc1LMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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