SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c43fbadba5e90deb57908e64ed631746160cb9b40c9bc99afffa89077361296' 
  AND token = 'iBTt3QsrKtoe61D52Na4Pwppj3JoSwrNUVQGSmZnm+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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