SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc6e25081a1770ab0737d53687b4a9edb65b204554505ba1474694275818053e' 
  AND token = 'ynpmZ5akMap99jTd2JxJQkz9BqsPOljtscT3zBopRqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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