SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f416d654d2282e7c64ede988ca91a75327b1fef84bf0f505ed9bd84991144354' 
  AND token = 'AJSs3pFRgHm3eOJnJ3vdFzkTtNBcvrhqCOPAZTGv5VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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