SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7a39a61f0f3afa6ce1d5f64a720f9151660ddd055920b1736fedbee861e93ba' 
  AND token = 'sxcAuZAb8ceoVDDuLau1lukaUJXdYUq4HPUzeQyC6/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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