SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c7749fde91b749825d94961d9338f7c0f343318b7cca4f404e6b57369a8aef8' 
  AND token = 'RmdSd+PBuZDhe5p7KxF9hxatYp3o99oYqJFK6gX2Rvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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