SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5c4e41870770cb50d448f172ec42c50096a746ea66b5dbcb8cc35b160d47f5a' 
  AND token = 'G7Xh06xEo/0W+Qb6VQsqxvxvq5ujDAsaFcSOZmVio9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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