SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7523a4193b9a1fee85fdfd575201b16ea5ee65ab74a4a7539cdcdcfce83070bb' 
  AND token = 'GglUekSCA4lcIUKrqiV5JIGCjFTD8JiDWDRJFcWUCmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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