SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92bc51bcda2bcf5790cf4b41079a00ee008fd991b460aa9c417680a63fcb3afb' 
  AND token = 'GpLbPmC7/l4wcUV8FXG63owciF4UESL3tS6R8IgSnXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}