SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32e0c0f8900745f6c2361733accca4df5a45079d977c71e7f26bec9f1ed71f6a' 
  AND token = 'Lxn+gYeFB6c/AKuswx4y/Ut4wO2pDPezYVzwlozZ1XY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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