SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2575ccfd429e979ad3f9082d5a4fa9933b73ee959ae82c5a79dfb46fba8a0a48' 
  AND token = 'FrjfC5IKSJXXLx9SWszAm6aYDN1rRD61WGYtvx3rM0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}