SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3fae377c873c55361d01ac5403a36fe1a652c1a446996d1269bcbc8c6194d47' 
  AND token = 'lO2sy53FvBIPaStYNLaYxGXaiXkto/Ocpg1OkEChrzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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