SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7163837a74b162efc90e680e219149288b77bb9663d0f9861ae963b9118855b' 
  AND token = 'rVupoh4dHIcNnTc3KsDDBoQRLEDpxGwNIP6/3ZzEigs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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