SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08ae43f0122d2b2841426ebb5bbeaa7e47e1cc888d7db1a68d43fad7bd784ae0' 
  AND token = '3gmsTpdq4qrK7/XWPYLEnv511bxnB6NHhA0cf1OQqxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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