SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7468485d1e56f70ca90daaf6f56cd3cb7e4f60576f013a828ec4bea98927ccb3' 
  AND token = 'RWOiEkWaNoHfG8RLMbAmo177CEY503Nsr6MMkIwMEn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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