SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3729671fc32756e72d4fcce26981d5323e8c6b971c0b7d51e4f16803f754eefb' 
  AND token = 'NYCW6Bm8gMJjAXOLhkyh9DRYayWw7VKDonjcAVY3gSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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