SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b159cc7fac7a55c6ba90778b550481ccf5a45e522d9110dbab345491deac582' 
  AND token = '7gS0E1SLOf9BYDlHjWZhnGpo5sutiJpnFz0oO7TrCBQ=' 
  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"
    }
  }
}