SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2d4f564d85cb2422af65bfcc21afbf96372158c8aeeaf398206c4a691bfc89a2' 
  AND token = 'MRcffYglXyAuG6hhZXHpUop0hYIflVT8OJ8Fn40+7EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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