SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34d46db902202e6fd9ce6bd41e834a54b5129f6c8fc61fa2fc9191d5b82c1b48' 
  AND token = 'puoLkAXGxgcfYEpBRaClZlhSsVuKj2eEOC1WWYJQN4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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