SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824afafc54b7808b9219763d0e14e9545daca4b8c18f5df5e4126b60f002d0e4' 
  AND token = 'R8roPbd3gEiRrbDz8lVBaD1x43Y6YbvF85oHS39Udfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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