SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2f522513f3a6a0a902dadf4d3e134bf2b47482adcec4d2a2e059dbabe950553' 
  AND token = 'c05vkV4VlBb3UGKjEUTWtjiinAIAcSQj2RfNOnC9LJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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