SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff4d0dfeadd81cb85dac22d267acd52246e2674933a31f46999bb5939ab9b015' 
  AND token = 'qvUjmEZSzfd4LOtINdeDHzQcj4AzcWha75qQdzkCV28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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