SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8507543bd793e5f9921223a77395bb4b53006afa33e90ce9bf3c5226556bd3ec' 
  AND token = 'TFhQw82xNAJmwWssGJzfwCmaxIwTN5AfyWnUKjR+b3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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