SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d347022f506913420aac06888ac2b2b06fbeca6a12033700fe8ba592de7305a' 
  AND token = 'QVyoAzL1geWTrQAvCnhX8SpW0XXyFkPpTRAY4oLl6D0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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