SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fd54052a64bfc32c5866e585fd6bc1f2cd1a32b2bf0c8cf1778aa341e70590e' 
  AND token = 's1a+L5JvQm/otEOYzVXCvEcJSR/dOG1zw+ExJfrGDh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00081

JSON explain

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