SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd587921c22c9f2b1fdc033f41e44d832a97526a4ece7a66cbded87416982728' 
  AND token = 'HD9RuKH7IFw1aE+lKRn8NLK4QRyq1jayrgCsgK7At/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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