SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd34a063bd862a5796bd3d8b4fc263c345981aa0272e557de010938bfac5ecc7e' 
  AND token = 'j+Dw7adMpS5Q1mTbG8rYoj3dL9WYRBhAjHgnwhXWa4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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