SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd871222eb7d56bf4201085643baa3b3fc0bba423541b5e309efe1df72709ab6' 
  AND token = '1rUHSYd0601WtHgGzkdxouwMj8kvZBpsoE3bJp8rm7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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