SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b6250dff9e6ef37de390ee8768a5f819bbfc34abc5a8a337de9d0df9988048c' 
  AND token = 'Jcvvg2X9Sq6iGhgYlRQwjkvI+i4Dr/2pmVmt/U1o8X0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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