SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53c35fbe6915c11b57e708caffbfb47164aff2ffbcdfb264ca032f3c0b81b7de' 
  AND token = '8c/cg5cRp1WaTotqCzUOeuVCAKHPImDkqxJPcVD8kQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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