SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b04066de513254ea043456a5888fa0814432c333b76c1e6d058597972ae4d06' 
  AND token = 'zTTW5MKLgR6g18d3Qn6lvf6Fe0aGjKDZIyMuPvbfrbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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