SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c203bc2973b898869228a0bfb725adddef3e79e4bd5e015d221b3bbedc524f9' 
  AND token = 'nX/jBqlQZlHZQ4j5zXwk08lHKG37CGv5vsfxSw4qWso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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