SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '83cf55b467c748852e6a7ab3dca276e54cd6038e1df430ad5f89dade775e2552' 
  AND token = 'jJnU35QF98G/Ft9bZUrLvKJ24yuz4xHIGozdKhpkpcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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