SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac098b3dcf4c0da70d2b22eaab2086435b17647c569da1a08e1536a9de24aba1' 
  AND token = 'LUs/+OYGPi2tIkzm4qNAyP8f14SP8Tiedr96CkODsH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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