SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6ae4d62a808f9bab6581a94515d6e1d03ffb990b120b03a4798acb1fc6decbd' 
  AND token = 'dP1/SFqk8R+hQhVBnxJImiy80vgaFCwjyjqX6/QIhfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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