SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd4811111363aeb8a025089c45e367d74e12fc363baf1e1b53113f317597a7cf' 
  AND token = 'UgH1EE4YKdORnrIiwTIq57SfCzYRsjoAxFoTbswQhFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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