SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6252f148cb476b9b6a04ee69899464b18c37cf1433824e508b00d36bd7a980c0' 
  AND token = '3zh8vbCAEi+szsYb6aH1clTKFKtccWrqBePAb3i4f9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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